AFAIK, dir structure MUST be the same , i.e,
same names , same sizes , etc
I dunno if you are on a UNIX platfform , though.
One thing that might be very helpful in these
situations is to use soft links ( UNIX )
When planning a database it's
very useful to assign chuncks to soft links,e.g.,
in your dev directory , you could have
/dev/rootdbs -> /dev/vg01/rlvol6
later you could point rootdbs to another device
of same size , if needed